1. Technical Field of the Invention
The invention relates, as novel and useful industrial products, to triaromatic compounds which are vitamin D analogues.
The invention also relates to a process for preparing them and to their use in pharmaceutical compositions intended for use in human or veterinary medicine, or alternatively in cosmetic compositions.
The compounds according to the invention have pronounced activity in the fields of cell proliferation and differentiation and find applications more particularly in the topical and systemic treatment of dermatological (or other) complaints associated with a keratinization disorder, complaints with an inflammatory and/or immunoallergic component and hyperproliferation of tissues of ectodermal origin (skin, epithelium, etc.), whether benign or malignant. These compounds can also be used to combat aging of the skin, whether photo-induced or chronological, and to treat cicatrization disorders.
The compounds according to the invention can also be used in cosmetic compositions for body and hair hygiene.
2. Description of the Prior Art
Vitamin D is an essential vitamin for preventing and treating mineralization defects of cartilage (rickets) and of bone (osteomalacia), and even of certain forms of osteoporosis in elderly people. However, it is now accepted that its functions extend well beyond regulating bone metabolism and calcium homeostasis. Among these functions, mention may be made of its actions on cell proliferation and differentiation and the control of the immune defenses. Their discovery has opened the way to novel therapeutic approaches in dermatology, carcinology and in the field of autoimmune diseases and that of organ or tissue transplants.
An efficient therapeutic supply has long been confounded by the toxicity of this vitamin (occasionally fatal hypercalcaemia). Structural analogues of vitamin D are currently synthesized, some of which conserve only the differentiating properties and have no action on calcium metabolism.
The Applicant has already proposed, in patent application WO 01/38303, novel compounds that are vitamin D analogues, which show selective activity on cell proliferation and differentiation without having a hypercalcaemiant nature.